STRUCTURAL 



139 



A thickness of 14 in., i.e., one and a half brick 

 is the usual standard, and will serve any wall up 

 to 12 ft. Greater heights should be built 18 in. 

 Under 7 ft. 9 in. is sufficiently strong, but it is 

 impossible to build neatly on both sides with the 



'lii.il. ~ 



J I. I 



1 1 



II II 111 



I . I ,\ 



DIAGRAM 49. 



one brick thickness, even using the " garden wall " 

 bond (Diagram 49). This, however, is not always 

 considered a prohibitory objection, and with the 

 added strength of piers, 9 in. walls are often made 

 over 8 ft. The piers would be from 12 to 14 ft. 

 apart so as not to interfere with the training of 

 fruit trees, and be 22 J in. wide, projecting 4^ in. 



DIAGRAM 50. 



from the face of the wall. They need not go right 

 to the top, and should be protected by a coping 

 at the finish. Walls built with recesses, as in 

 Diagram 50, give a fine appearance to a formal 

 design. 



